Commit Graph

228 Commits

Author SHA1 Message Date
Linus Torvalds 77c688ac87 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "The big thing in this pile is Eric's unmount-on-rmdir series; we
  finally have everything we need for that.  The final piece of prereqs
  is delayed mntput() - now filesystem shutdown always happens on
  shallow stack.

  Other than that, we have several new primitives for iov_iter (Matt
  Wilcox, culled from his XIP-related series) pushing the conversion to
  ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c
  cleanups and fixes (including the external name refcounting, which
  gives consistent behaviour of d_move() wrt procfs symlinks for long
  and short names alike) and assorted cleanups and fixes all over the
  place.

  This is just the first pile; there's a lot of stuff from various
  people that ought to go in this window.  Starting with
  unionmount/overlayfs mess...  ;-/"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits)
  fs/file_table.c: Update alloc_file() comment
  vfs: Deduplicate code shared by xattr system calls operating on paths
  reiserfs: remove pointless forward declaration of struct nameidata
  don't need that forward declaration of struct nameidata in dcache.h anymore
  take dname_external() into fs/dcache.c
  let path_init() failures treated the same way as subsequent link_path_walk()
  fix misuses of f_count() in ppp and netlink
  ncpfs: use list_for_each_entry() for d_subdirs walk
  vfs: move getname() from callers to do_mount()
  gfs2_atomic_open(): skip lookups on hashed dentry
  [infiniband] remove pointless assignments
  gadgetfs: saner API for gadgetfs_create_file()
  f_fs: saner API for ffs_sb_create_file()
  jfs: don't hash direct inode
  [s390] remove pointless assignment of ->f_op in vmlogrdr ->open()
  ecryptfs: ->f_op is never NULL
  android: ->f_op is never NULL
  nouveau: __iomem misannotations
  missing annotation in fs/file.c
  fs: namespace: suppress 'may be used uninitialized' warnings
  ...
2014-10-13 11:28:42 +02:00
Tetsuo Handa 475d0db742 fs: Fix theoretical division by 0 in super_cache_scan().
total_objects could be 0 and is used as a denom.

While total_objects is a "long", total_objects == 0 unlikely happens for
3.12 and later kernels because 32-bit architectures would not be able to
hold (1 << 32) objects. However, total_objects == 0 may happen for kernels
between 3.1 and 3.11 because total_objects in prune_super() was an "int"
and (e.g.) x86_64 architecture might be able to hold (1 << 32) objects.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable <stable@kernel.org> # 3.1+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09 02:39:02 -04:00
Tejun Heo 908c7f1949 percpu_counter: add @gfp to percpu_counter_init()
Percpu allocator now supports allocation mask.  Add @gfp to
percpu_counter_init() so that !GFP_KERNEL allocation masks can be used
with percpu_counters too.

We could have left percpu_counter_init() alone and added
percpu_counter_init_gfp(); however, the number of users isn't that
high and introducing _gfp variants to all percpu data structures would
be quite ugly, so let's just do the conversion.  This is the one with
the most users.  Other percpu data structures are a lot easier to
convert.

This patch doesn't make any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: x86@kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
2014-09-08 09:51:29 +09:00
Linus Torvalds cec997093b Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull quota, reiserfs, UDF updates from Jan Kara:
 "Scalability improvements for quota, a few reiserfs fixes, and couple
  of misc cleanups (udf, ext2)"

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  reiserfs: Fix use after free in journal teardown
  reiserfs: fix corruption introduced by balance_leaf refactor
  udf: avoid redundant memcpy when writing data in ICB
  fs/udf: re-use hex_asc_upper_{hi,lo} macros
  fs/quota: kernel-doc warning fixes
  udf: use linux/uaccess.h
  fs/ext2/super.c: Drop memory allocation cast
  quota: remove dqptr_sem
  quota: simplify remove_inode_dquot_ref()
  quota: avoid unnecessary dqget()/dqput() calls
  quota: protect Q_GETFMT by dqonoff_mutex
2014-08-13 17:45:40 -06:00
Al Viro 8fa1f1c2bd make fs/{namespace,super}.c forget about acct.h
These externs belong in fs/internal.h.  Rename (they are not acct-specific
anymore) and move them over there.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:09 -04:00
Al Viro 0aec09d049 drop ->s_umount around acct_auto_close()
just repeat the frozen check after regaining it, and check that sb
is still alive.  If several threads hit acct_auto_close() at the
same time, acct_auto_close() will survive that just fine.  And we
really don't want to play with writes and closing the file with
->s_umount held exclusive - it's a deadlock country.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Al Viro 215752fce3 acct: get rid of acct_list
Put these suckers on per-vfsmount and per-superblock lists instead.
Note: right now it's still acct_lock for everything, but that's
going to change.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Niu Yawei b9ba6f94b2 quota: remove dqptr_sem
Remove dqptr_sem to make quota code scalable: Remove the dqptr_sem,
accessing inode->i_dquot now protected by dquot_srcu, and changing
inode->i_dquot is now serialized by dq_data_lock.

Signed-off-by: Lai Siyao <lai.siyao@intel.com>
Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2014-07-15 22:40:22 +02:00
Tim Chen d23da150a3 fs/superblock: avoid locking counting inodes and dentries before reclaiming them
We remove the call to grab_super_passive in call to super_cache_count.
This becomes a scalability bottleneck as multiple threads are trying to do
memory reclamation, e.g.  when we are doing large amount of file read and
page cache is under pressure.  The cached objects quickly got reclaimed
down to 0 and we are aborting the cache_scan() reclaim.  But counting
creates a log jam acquiring the sb_lock.

We are holding the shrinker_rwsem which ensures the safety of call to
list_lru_count_node() and s_op->nr_cached_objects.  The shrinker is
unregistered now before ->kill_sb() so the operation is safe when we are
doing unmount.

The impact will depend heavily on the machine and the workload but for a
small machine using postmark tuned to use 4xRAM size the results were

                                  3.15.0-rc5            3.15.0-rc5
                                     vanilla         shrinker-v1r1
Ops/sec Transactions         21.00 (  0.00%)       24.00 ( 14.29%)
Ops/sec FilesCreate          39.00 (  0.00%)       44.00 ( 12.82%)
Ops/sec CreateTransact       10.00 (  0.00%)       12.00 ( 20.00%)
Ops/sec FilesDeleted       6202.00 (  0.00%)     6202.00 (  0.00%)
Ops/sec DeleteTransact       11.00 (  0.00%)       12.00 (  9.09%)
Ops/sec DataRead/MB          25.97 (  0.00%)       29.10 ( 12.05%)
Ops/sec DataWrite/MB         49.99 (  0.00%)       56.02 ( 12.06%)

ffsb running in a configuration that is meant to simulate a mail server showed

                                 3.15.0-rc5             3.15.0-rc5
                                    vanilla          shrinker-v1r1
Ops/sec readall           9402.63 (  0.00%)      9567.97 (  1.76%)
Ops/sec create            4695.45 (  0.00%)      4735.00 (  0.84%)
Ops/sec delete             173.72 (  0.00%)       179.83 (  3.52%)
Ops/sec Transactions     14271.80 (  0.00%)     14482.81 (  1.48%)
Ops/sec Read                37.00 (  0.00%)        37.60 (  1.62%)
Ops/sec Write               18.20 (  0.00%)        18.30 (  0.55%)

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:11 -07:00
Dave Chinner 28f2cd4f6d fs/superblock: unregister sb shrinker before ->kill_sb()
This series is aimed at regressions noticed during reclaim activity.  The
first two patches are shrinker patches that were posted ages ago but never
merged for reasons that are unclear to me.  I'm posting them again to see
if there was a reason they were dropped or if they just got lost.  Dave?
Time?  The last patch adjusts proportional reclaim.  Yuanhan Liu, can you
retest the vm scalability test cases on a larger machine?  Hugh, does this
work for you on the memcg test cases?

Based on ext4, I get the following results but unfortunately my larger
test machines are all unavailable so this is based on a relatively small
machine.

postmark
                                  3.15.0-rc5            3.15.0-rc5
                                     vanilla       proportion-v1r4
Ops/sec Transactions         21.00 (  0.00%)       25.00 ( 19.05%)
Ops/sec FilesCreate          39.00 (  0.00%)       45.00 ( 15.38%)
Ops/sec CreateTransact       10.00 (  0.00%)       12.00 ( 20.00%)
Ops/sec FilesDeleted       6202.00 (  0.00%)     6202.00 (  0.00%)
Ops/sec DeleteTransact       11.00 (  0.00%)       12.00 (  9.09%)
Ops/sec DataRead/MB          25.97 (  0.00%)       30.02 ( 15.59%)
Ops/sec DataWrite/MB         49.99 (  0.00%)       57.78 ( 15.58%)

ffsb (mail server simulator)
                                 3.15.0-rc5             3.15.0-rc5
                                    vanilla        proportion-v1r4
Ops/sec readall           9402.63 (  0.00%)      9805.74 (  4.29%)
Ops/sec create            4695.45 (  0.00%)      4781.39 (  1.83%)
Ops/sec delete             173.72 (  0.00%)       177.23 (  2.02%)
Ops/sec Transactions     14271.80 (  0.00%)     14764.37 (  3.45%)
Ops/sec Read                37.00 (  0.00%)        38.50 (  4.05%)
Ops/sec Write               18.20 (  0.00%)        18.50 (  1.65%)

dd of a large file
                                3.15.0-rc5            3.15.0-rc5
                                   vanilla       proportion-v1r4
WallTime DownloadTar       75.00 (  0.00%)       61.00 ( 18.67%)
WallTime DD               423.00 (  0.00%)      401.00 (  5.20%)
WallTime Delete             2.00 (  0.00%)        5.00 (-150.00%)

stutter (times mmap latency during large amounts of IO)

                            3.15.0-rc5            3.15.0-rc5
                               vanilla       proportion-v1r4
Unit >5ms Delays  80252.0000 (  0.00%)  81523.0000 ( -1.58%)
Unit Mmap min         8.2118 (  0.00%)      8.3206 ( -1.33%)
Unit Mmap mean       17.4614 (  0.00%)     17.2868 (  1.00%)
Unit Mmap stddev     24.9059 (  0.00%)     34.6771 (-39.23%)
Unit Mmap max      2811.6433 (  0.00%)   2645.1398 (  5.92%)
Unit Mmap 90%        20.5098 (  0.00%)     18.3105 ( 10.72%)
Unit Mmap 93%        22.9180 (  0.00%)     20.1751 ( 11.97%)
Unit Mmap 95%        25.2114 (  0.00%)     22.4988 ( 10.76%)
Unit Mmap 99%        46.1430 (  0.00%)     43.5952 (  5.52%)
Unit Ideal  Tput     85.2623 (  0.00%)     78.8906 (  7.47%)
Unit Tput min        44.0666 (  0.00%)     43.9609 (  0.24%)
Unit Tput mean       45.5646 (  0.00%)     45.2009 (  0.80%)
Unit Tput stddev      0.9318 (  0.00%)      1.1084 (-18.95%)
Unit Tput max        46.7375 (  0.00%)     46.7539 ( -0.04%)

This patch (of 3):

We will like to unregister the sb shrinker before ->kill_sb().  This will
allow cached objects to be counted without call to grab_super_passive() to
update ref count on sb.  We want to avoid locking during memory
reclamation especially when we are skipping the memory reclaim when we are
out of cached objects.

This is safe because grab_super_passive does a try-lock on the
sb->s_umount now, and so if we are in the unmount process, it won't ever
block.  That means what used to be a deadlock and races we were avoiding
by using grab_super_passive() is now:

        shrinker                        umount

        down_read(shrinker_rwsem)
                                        down_write(sb->s_umount)
                                        shrinker_unregister
                                          down_write(shrinker_rwsem)
                                            <blocks>
        grab_super_passive(sb)
          down_read_trylock(sb->s_umount)
            <fails>
        <shrinker aborts>
        ....
        <shrinkers finish running>
        up_read(shrinker_rwsem)
                                          <unblocks>
                                          <removes shrinker>
                                          up_write(shrinker_rwsem)
                                        ->kill_sb()
                                        ....

So it is safe to deregister the shrinker before ->kill_sb().

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:11 -07:00
Thomas Bächler a2a4dc494a fs: Don't return 0 from get_anon_bdev
Commit 9e30cc9595 removed an internal mount. This
has the side-effect that rootfs now has FSID 0. Many
userspace utilities assume that st_dev in struct stat
is never 0, so this change breaks a number of tools in
early userspace.

Since we don't know how many userspace programs are affected,
make sure that FSID is at least 1.

References: http://article.gmane.org/gmane.linux.kernel/1666905
References: http://permalink.gmane.org/gmane.linux.utilities.util-linux-ng/8557
Cc: 3.14 <stable@vger.kernel.org>
Signed-off-by: Thomas Bächler <thomas@archlinux.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Tested-by: Alexandre Demers <alexandre.f.demers@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-16 11:53:08 -07:00
Theodore Ts'o 02b9984d64 fs: push sync_filesystem() down to the file system's remount_fs()
Previously, the no-op "mount -o mount /dev/xxx" operation when the
file system is already mounted read-write causes an implied,
unconditional syncfs().  This seems pretty stupid, and it's certainly
documented or guaraunteed to do this, nor is it particularly useful,
except in the case where the file system was mounted rw and is getting
remounted read-only.

However, it's possible that there might be some file systems that are
actually depending on this behavior.  In most file systems, it's
probably fine to only call sync_filesystem() when transitioning from
read-write to read-only, and there are some file systems where this is
not needed at all (for example, for a pseudo-filesystem or something
like romfs).

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Jan Kara <jack@suse.cz>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Anders Larsen <al@alarsen.net>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: xfs@oss.sgi.com
Cc: linux-btrfs@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: codalist@coda.cs.cmu.edu
Cc: linux-ext4@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: fuse-devel@lists.sourceforge.net
Cc: cluster-devel@redhat.com
Cc: linux-mtd@lists.infradead.org
Cc: jfs-discussion@lists.sourceforge.net
Cc: linux-nfs@vger.kernel.org
Cc: linux-nilfs@vger.kernel.org
Cc: linux-ntfs-dev@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Cc: reiserfs-devel@vger.kernel.org
2014-03-13 10:14:33 -04:00
Andrew Ruder 807612db2f fs/super.c: sync ro remount after blocking writers
Move sync_filesystem() after sb_prepare_remount_readonly().  If writers
sneak in anywhere from sync_filesystem() to sb_prepare_remount_readonly()
it can cause inodes to be dirtied and writeback to occur well after
sys_mount() has completely successfully.

This was spotted by corrupted ubifs filesystems on reboot, but appears
that it can cause issues with any filesystem using writeback.

Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
CC: Richard Weinberger <richard@nod.at>
Co-authored-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-31 14:29:36 -05:00
Vladimir Davydov b5bd856a0c fs/super.c: fix WARN on alloc_super() fail path
On fail path alloc_super() calls destroy_super(), which issues a warning
if the sb's s_mounts list is not empty, in particular if it has not been
initialized.  That said s_mounts must be initialized in alloc_super()
before any possible failure, but currently it is initialized close to
the end of the function leading to a useless warning dumped to log if
either percpu_counter_init() or list_lru_init() fails.  Let's fix this.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21 16:19:42 -08:00
Al Viro eee5cc2702 get rid of s_files and files_lock
The only thing we need it for is alt-sysrq-r (emergency remount r/o)
and these days we can do just as well without going through the
list of files.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:20 -05:00
Al Viro e2fec7c355 make freeing super_block rcu-delayed
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24 23:43:26 -04:00
Al Viro 7eb5e88269 uninline destroy_super(), consolidate alloc_super()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24 23:35:00 -04:00
Al Viro c2d22ecd3c fs/super.c: fix lru_list leak for real
Freeing ->s_{inode,dentry}_lru in deactivate_locked_super() is wrong;
the right place is destroy_super().  As it is, we leak them if sget()
decides that new superblock it has allocated (and never shown to
anybody) isn't needed and should be freed.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-01 13:11:21 -04:00
Glauber Costa f5e1dd3456 super: fix for destroy lrus
This patch adds the missing call to list_lru_destroy (spotted by Li Zhong)
and moves the deletion to after the shrinker is unregistered, as correctly
spotted by Dave

Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:32 -04:00
Glauber Costa 5ca302c8e5 list_lru: dynamically adjust node arrays
We currently use a compile-time constant to size the node array for the
list_lru structure.  Due to this, we don't need to allocate any memory at
initialization time.  But as a consequence, the structures that contain
embedded list_lru lists can become way too big (the superblock for
instance contains two of them).

This patch aims at ameliorating this situation by dynamically allocating
the node arrays with the firmware provided nr_node_ids.

Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:32 -04:00
Dave Chinner 9b17c62382 fs: convert inode and dentry shrinking to be node aware
Now that the shrinker is passing a node in the scan control structure, we
can pass this to the the generic LRU list code to isolate reclaim to the
lists on matching nodes.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:31 -04:00
Dave Chinner f604156751 dcache: convert to use new lru list infrastructure
[glommer@openvz.org: don't reintroduce double decrement of nr_unused_dentries, adapted for new LRU return codes]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:30 -04:00
Dave Chinner bc3b14cb2d inode: convert inode lru list to generic lru list code.
[glommer@openvz.org: adapted for new LRU return codes]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:30 -04:00
Dave Chinner 0a234c6dcb shrinker: convert superblock shrinkers to new API
Convert superblock shrinker to use the new count/scan API, and propagate
the API changes through to the filesystem callouts.  The filesystem
callouts already use a count/scan API, so it's just changing counters to
longs to match the VM API.

This requires the dentry and inode shrinker callouts to be converted to
the count/scan API.  This is mainly a mechanical change.

[glommer@openvz.org: use mult_frac for fractional proportions, build fixes]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:30 -04:00
Dave Chinner 19156840e3 dentry: move to per-sb LRU locks
With the dentry LRUs being per-sb structures, there is no real need for
a global dentry_lru_lock. The locking can be made more fine-grained by
moving to a per-sb LRU lock, isolating the LRU operations of different
filesytsems completely from each other. The need for this is independent
of any performance consideration that may arise: in the interest of
abstracting the lru operations away, it is mandatory that each lru works
around its own lock instead of a global lock for all of them.

[glommer@openvz.org: updated changelog ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:30 -04:00
Glauber Costa 55f841ce93 super: fix calculation of shrinkable objects for small numbers
The sysctl knob sysctl_vfs_cache_pressure is used to determine which
percentage of the shrinkable objects in our cache we should actively try
to shrink.

It works great in situations in which we have many objects (at least more
than 100), because the aproximation errors will be negligible.  But if
this is not the case, specially when total_objects < 100, we may end up
concluding that we have no objects at all (total / 100 = 0, if total <
100).

This is certainly not the biggest killer in the world, but may matter in
very low kernel memory situations.

Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:29 -04:00
Al Viro d040790391 prune_super(): sb->s_op is never NULL
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-07 19:54:56 -04:00
Christoph Hellwig 7b7a8665ed direct-io: Implement generic deferred AIO completions
Add support to the core direct-io code to defer AIO completions to user
context using a workqueue.  This replaces opencoded and less efficient
code in XFS and ext4 (we save a memory allocation for each direct IO)
and will be needed to properly support O_(D)SYNC for AIO.

The communication between the filesystem and the direct I/O code requires
a new buffer head flag, which is a bit ugly but not avoidable until the
direct I/O code stops abusing the buffer_head structure for communicating
with the filesystems.

Currently this creates a per-superblock unbound workqueue for these
completions, which is taken from an earlier patch by Jan Kara.  I'm
not really convinced about this use and would prefer a "normal" global
workqueue with a high concurrency limit, but this needs further discussion.

JK: Fixed ext4 part, dynamic allocation of the workqueue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-04 09:23:46 -04:00
Al Viro acfec9a5a8 livelock avoidance in sget()
Eric Sandeen has found a nasty livelock in sget() - take a mount(2) about
to fail.  The superblock is on ->fs_supers, ->s_umount is held exclusive,
->s_active is 1.  Along comes two more processes, trying to mount the same
thing; sget() in each is picking that superblock, bumping ->s_count and
trying to grab ->s_umount.  ->s_active is 3 now.  Original mount(2)
finally gets to deactivate_locked_super() on failure; ->s_active is 2,
superblock is still ->fs_supers because shutdown will *not* happen until
->s_active hits 0.  ->s_umount is dropped and now we have two processes
chasing each other:
s_active = 2, A acquired ->s_umount, B blocked
A sees that the damn thing is stillborn, does deactivate_locked_super()
s_active = 1, A drops ->s_umount, B gets it
A restarts the search and finds the same superblock.  And bumps it ->s_active.
s_active = 2, B holds ->s_umount, A blocked on trying to get it
... and we are in the earlier situation with A and B switched places.

The root cause, of course, is that ->s_active should not grow until we'd
got MS_BORN.  Then failing ->mount() will have deactivate_locked_super()
shut the damn thing down.  Fortunately, it's easy to do - the key point
is that grab_super() is called only for superblocks currently on ->fs_supers,
so it can bump ->s_count and grab ->s_umount first, then check MS_BORN and
bump ->s_active; we must never increment ->s_count for superblocks past
->kill_sb(), but grab_super() is never called for those.

The bug is pretty old; we would've caught it by now, if not for accidental
exclusion between sget() for block filesystems; the things like cgroup or
e.g. mtd-based filesystems don't have anything of that sort, so they get
bitten.  The right way to deal with that is obviously to fix sget()...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-20 04:58:58 +04:00
Sasha Levin b67bfe0d42 hlist: drop the node parameter from iterators
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:24 -08:00
Tejun Heo e8c8d1bc06 idr: remove MAX_IDR_MASK and move left MAX_IDR_* into idr.c
MAX_IDR_MASK is another weirdness in the idr interface.  As idr covers
whole positive integer range, it's defined as 0x7fffffff or INT_MAX.

Its usage in idr_find(), idr_replace() and idr_remove() is bizarre.
They basically mask off the sign bit and operate on the rest, so if
the caller, by accident, passes in a negative number, the sign bit
will be masked off and the remaining part will be used as if that was
the input, which is worse than crashing.

The constant is visible in idr.h and there are several users in the
kernel.

* drivers/i2c/i2c-core.c:i2c_add_numbered_adapter()

  Basically used to test if adap->nr is a negative number which isn't
  -1 and returns -EINVAL if so.  idr_alloc() already has negative
  @start checking (w/ WARN_ON_ONCE), so this can go away.

* drivers/infiniband/core/cm.c:cm_alloc_id()
  drivers/infiniband/hw/mlx4/cm.c:id_map_alloc()

  Used to wrap cyclic @start.  Can be replaced with max(next, 0).
  Note that this type of cyclic allocation using idr is buggy.  These
  are prone to spurious -ENOSPC failure after the first wraparound.

* fs/super.c:get_anon_bdev()

  The ID allocated from ida is masked off before being tested whether
  it's inside valid range.  ida allocated ID can never be a negative
  number and the masking is unnecessary.

Update idr_*() functions to fail with -EINVAL when negative @id is
specified and update other MAX_IDR_MASK users as described above.

This leaves MAX_IDR_MASK without any user, remove it and relocate
other MAX_IDR_* constants to lib/idr.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Roland Dreier <roland@kernel.org>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: "Marciniszyn, Mike" <mike.marciniszyn@intel.com>
Cc: Jack Morgenstein <jackm@dev.mellanox.co.il>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Wolfram Sang <wolfram@the-dreams.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:20 -08:00
Marco Stornelli 8e22cc88d6 vfs: drop lock/unlock super
Removed s_lock from super_block and removed lock/unlock super.

Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-09 23:33:39 -04:00
Fengguang Wu 125c4c706b idr: rename MAX_LEVEL to MAX_IDR_LEVEL
To avoid name conflicts:

  drivers/video/riva/fbdev.c:281:9: sparse: preprocessor token MAX_LEVEL redefined

While at it, also make the other names more consistent and add
parentheses.

[akpm@linux-foundation.org: repair fallout]
[sfr@canb.auug.org.au: IB/mlx4: fix for MAX_ID_MASK to MAX_IDR_MASK name change]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: walter harms <wharms@bfs.de>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:04:56 +09:00
Kirill A. Shutemov 8c0a853770 fs: push rcu_barrier() from deactivate_locked_super() to filesystems
There's no reason to call rcu_barrier() on every
deactivate_locked_super().  We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.

Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths.  E.g.  on my machine exit_group() of a last process in IPC
namespace takes 0.07538s.  rcu_barrier() takes 0.05188s of that time.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-02 21:35:55 -04:00
Artem Bityutskiy f0cd2dbb6c vfs: kill write_super and sync_supers
Finally we can kill the 'sync_supers' kernel thread along with the
'->write_super()' superblock operation because all the users are gone.
Now every file-system is supposed to self-manage own superblock and
its dirty state.

The nice thing about killing this thread is that it improves power management.
Indeed, 'sync_supers' is a source of monotonic system wake-ups - it woke up
every 5 seconds no matter what - even if there were no dirty superblocks and
even if there were no file-systems using this service (e.g., btrfs and
journalled ext4 do not need it). So it was wasting power most of the time. And
because the thread was in the core of the kernel, all systems had to have it.
So I am quite happy to make it go away.

Interestingly, this thread is a left-over from the pdflush kernel thread which
was a self-forking kernel thread responsible for all the write-back in old
Linux kernels. It was turned into per-block device BDI threads, and
'sync_supers' was a left-over. Thus, R.I.P, pdflush as well.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-08-04 01:24:44 +04:00
Linus Torvalds a0e881b7c1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second vfs pile from Al Viro:
 "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the
  deadlock reproduced by xfstests 068), symlink and hardlink restriction
  patches, plus assorted cleanups and fixes.

  Note that another fsfreeze deadlock (emergency thaw one) is *not*
  dealt with - the series by Fernando conflicts a lot with Jan's, breaks
  userland ABI (FIFREEZE semantics gets changed) and trades the deadlock
  for massive vfsmount leak; this is going to be handled next cycle.
  There probably will be another pull request, but that stuff won't be
  in it."

Fix up trivial conflicts due to unrelated changes next to each other in
drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c}

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
  delousing target_core_file a bit
  Documentation: Correct s_umount state for freeze_fs/unfreeze_fs
  fs: Remove old freezing mechanism
  ext2: Implement freezing
  btrfs: Convert to new freezing mechanism
  nilfs2: Convert to new freezing mechanism
  ntfs: Convert to new freezing mechanism
  fuse: Convert to new freezing mechanism
  gfs2: Convert to new freezing mechanism
  ocfs2: Convert to new freezing mechanism
  xfs: Convert to new freezing code
  ext4: Convert to new freezing mechanism
  fs: Protect write paths by sb_start_write - sb_end_write
  fs: Skip atime update on frozen filesystem
  fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
  fs: Improve filesystem freezing handling
  switch the protection of percpu_counter list to spinlock
  nfsd: Push mnt_want_write() outside of i_mutex
  btrfs: Push mnt_want_write() outside of i_mutex
  fat: Push mnt_want_write() outside of i_mutex
  ...
2012-08-01 10:26:23 -07:00
Minchan Kim 8e125cd855 vmscan: remove obsolete shrink_control comment
09f363c7 ("vmscan: fix shrinker callback bug in fs/super.c") fixed a
shrinker callback which was returning -1 when nr_to_scan is zero, which
caused excessive slab scanning.  But 635697c6 ("vmscan: fix initial
shrinker size handling") fixed the problem, again so we can freely return
-1 although nr_to_scan is zero.  So let's revert 09f363c7 because the
comment added in 09f363c7 made an unnecessary rule.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:43 -07:00
Jan Kara d9c95bdd53 fs: Remove old freezing mechanism
Now that all users are converted, we can remove functions, variables, and
constants defined by the old freezing mechanism.

BugLink: https://bugs.launchpad.net/bugs/897421
Tested-by: Kamal Mostafa <kamal@canonical.com>
Tested-by: Peter M. Petrakis <peter.petrakis@canonical.com>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Tested-by: Massimo Morana <massimo.morana@canonical.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31 09:45:54 +04:00
Jan Kara 5accdf82ba fs: Improve filesystem freezing handling
vfs_check_frozen() tests are racy since the filesystem can be frozen just after
the test is performed. Thus in write paths we can end up marking some pages or
inodes dirty even though the file system is already frozen. This creates
problems with flusher thread hanging on frozen filesystem.

Another problem is that exclusion between ->page_mkwrite() and filesystem
freezing has been handled by setting page dirty and then verifying s_frozen.
This guaranteed that either the freezing code sees the faulted page, writes it,
and writeprotects it again or we see s_frozen set and bail out of page fault.
This works to protect from page being marked writeable while filesystem
freezing is running but has an unpleasant artefact of leaving dirty (although
unmodified and writeprotected) pages on frozen filesystem resulting in similar
problems with flusher thread as the first problem.

This patch aims at providing exclusion between write paths and filesystem
freezing. We implement a writer-freeze read-write semaphore in the superblock.
Actually, there are three such semaphores because of lock ranking reasons - one
for page fault handlers (->page_mkwrite), one for all other writers, and one of
internal filesystem purposes (used e.g. to track running transactions).  Write
paths which should block freezing (e.g. directory operations, ->aio_write(),
->page_mkwrite) hold reader side of the semaphore. Code freezing the filesystem
takes the writer side.

Only that we don't really want to bounce cachelines of the semaphores between
CPUs for each write happening. So we implement the reader side of the semaphore
as a per-cpu counter and the writer side is implemented using s_writers.frozen
superblock field.

[AV: microoptimize sb_start_write(); we want it fast in normal case]

BugLink: https://bugs.launchpad.net/bugs/897421
Tested-by: Kamal Mostafa <kamal@canonical.com>
Tested-by: Peter M. Petrakis <peter.petrakis@canonical.com>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Tested-by: Massimo Morana <massimo.morana@canonical.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31 09:30:13 +04:00
Linus Torvalds 2e3ee61348 Use time based periods to age the writeback proportions,
which can adapt equally well to fast/slow devices.
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Merge tag 'writeback-proportions' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux

Pull writeback updates from Wu Fengguang:
 "Use time based periods to age the writeback proportions, which can
  adapt equally well to fast/slow devices."

Fix up trivial conflict in comment in fs/sync.c

* tag 'writeback-proportions' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: Fix some comment errors
  block: Convert BDI proportion calculations to flexible proportions
  lib: Fix possible deadlock in flexible proportion code
  lib: Proportions with flexible period
2012-07-30 22:14:04 -07:00
David Howells 9249e17fe0 VFS: Pass mount flags to sget()
Pass mount flags to sget() so that it can use them in initialising a new
superblock before the set function is called.  They could also be passed to the
compare function.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:38:34 +04:00
Wanpeng Li 331cbdeede writeback: Fix some comment errors
Signed-off-by: Wanpeng Li <liwp@linux.vnet.ibm.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
2012-06-09 19:54:47 +08:00
Linus Torvalds 11bcb32848 The following text was taken from the original review request:
"[PATCH 0/3] RFC - module.h usage cleanups in fs/ and lib/"
 		https://lkml.org/lkml/2012/2/29/589
 --
 
 Fix up files in fs/ and lib/ dirs to only use module.h if they really
 need it.
 
 These are trivial in scope vs. the work done previously.  We now have
 things where any few remaining cleanups can be farmed out to arch or
 subsystem maintainers, and I have done so when possible.  What is
 remaining here represents the bits that don't clearly lie within a
 single arch/subsystem boundary, like the fs dir and the lib dir.
 
 Some duplicate includes arising from overlapping fixes from
 independent subsystem maintainer submissions are also quashed.
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Merge tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

Pull cleanup of fs/ and lib/ users of module.h from Paul Gortmaker:
 "Fix up files in fs/ and lib/ dirs to only use module.h if they really
  need it.

  These are trivial in scope vs the work done previously.  We now have
  things where any few remaining cleanups can be farmed out to arch or
  subsystem maintainers, and I have done so when possible.  What is
  remaining here represents the bits that don't clearly lie within a
  single arch/subsystem boundary, like the fs dir and the lib dir.

  Some duplicate includes arising from overlapping fixes from
  independent subsystem maintainer submissions are also quashed."

Fix up trivial conflicts due to clashes with other include file cleanups
(including some due to the previous bug.h cleanup pull).

* tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
  lib: reduce the use of module.h wherever possible
  fs: reduce the use of module.h wherever possible
  includecheck: delete any duplicate instances of module.h
2012-03-24 10:24:31 -07:00
Linus Torvalds aab008db80 Cleanups: rename of flush to invalidate, moving reporting of statistics
into debugfs, and use __read_mostly as neccessary.
 Also add a MAINTAINER file for cleancache API files.
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Merge tag 'stable/for-linus-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm

Pull cleancache changes from Konrad Rzeszutek Wilk:
 "This has some patches for the cleancache API that should have been
  submitted a _long_ time ago.  They are basically cleanups:

   - rename of flush to invalidate

   - moving reporting of statistics into debugfs

   - use __read_mostly as necessary.

  Oh, and also the MAINTAINERS file change.  The files (except the
  MAINTAINERS file) have been in #linux-next for months now.  The late
  addition of MAINTAINERS file is a brain-fart on my side - didn't
  realize I needed that just until I was typing this up - and I based
  that patch on v3.3 - so the tree is on top of v3.3."

* tag 'stable/for-linus-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm:
  MAINTAINERS: Adding cleancache API to the list.
  mm: cleancache: Use __read_mostly as appropiate.
  mm: cleancache: report statistics via debugfs instead of sysfs.
  mm: zcache/tmem/cleancache: s/flush/invalidate/
  mm: cleancache: s/flush/invalidate/
2012-03-22 19:52:47 -07:00
Linus Torvalds 3556485f15 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates for 3.4 from James Morris:
 "The main addition here is the new Yama security module from Kees Cook,
  which was discussed at the Linux Security Summit last year.  Its
  purpose is to collect miscellaneous DAC security enhancements in one
  place.  This also marks a departure in policy for LSM modules, which
  were previously limited to being standalone access control systems.
  Chromium OS is using Yama, and I believe there are plans for Ubuntu,
  at least.

  This patchset also includes maintenance updates for AppArmor, TOMOYO
  and others."

Fix trivial conflict in <net/sock.h> due to the jumo_label->static_key
rename.

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (38 commits)
  AppArmor: Fix location of const qualifier on generated string tables
  TOMOYO: Return error if fails to delete a domain
  AppArmor: add const qualifiers to string arrays
  AppArmor: Add ability to load extended policy
  TOMOYO: Return appropriate value to poll().
  AppArmor: Move path failure information into aa_get_name and rename
  AppArmor: Update dfa matching routines.
  AppArmor: Minor cleanup of d_namespace_path to consolidate error handling
  AppArmor: Retrieve the dentry_path for error reporting when path lookup fails
  AppArmor: Add const qualifiers to generated string tables
  AppArmor: Fix oops in policy unpack auditing
  AppArmor: Fix error returned when a path lookup is disconnected
  KEYS: testing wrong bit for KEY_FLAG_REVOKED
  TOMOYO: Fix mount flags checking order.
  security: fix ima kconfig warning
  AppArmor: Fix the error case for chroot relative path name lookup
  AppArmor: fix mapping of META_READ to audit and quiet flags
  AppArmor: Fix underflow in xindex calculation
  AppArmor: Fix dropping of allowed operations that are force audited
  AppArmor: Add mising end of structure test to caps unpacking
  ...
2012-03-21 13:25:04 -07:00
Konrad Rzeszutek Wilk 16c0cfa425 Merge branch 'stable/cleancache.v13' into linux-next
* stable/cleancache.v13:
  mm: cleancache: Use __read_mostly as appropiate.
  mm: cleancache: report statistics via debugfs instead of sysfs.
  mm: zcache/tmem/cleancache: s/flush/invalidate/
  mm: cleancache: s/flush/invalidate/
2012-03-19 12:12:19 -04:00
Paul Gortmaker 630d9c4727 fs: reduce the use of module.h wherever possible
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include.  Fix up any implicit
include dependencies that were being masked by module.h along
the way.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-28 19:31:58 -05:00
Jan Kara 6b6dc836a1 vfs: Provide function to get superblock and wait for it to thaw
In quota code we need to find a superblock corresponding to a device and wait
for superblock to be unfrozen. However this waiting has to happen without
s_umount semaphore because that is required for superblock to thaw. So provide
a function in VFS for this to keep dances with s_umount where they belong.

[AV: implementation switched to saner variant]

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-02-13 20:45:38 -05:00
Al Viro 4040153087 security: trim security.h
Trim security.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>
2012-02-14 10:45:42 +11:00
Dan Magenheimer 3167760f83 mm: cleancache: s/flush/invalidate/
Per akpm suggestions alter the use of the term flush to be
invalidate. The next patch will do this across all MM.

This change is completely cosmetic.

[v9: akpm@linux-foundation.org: change "flush" to "invalidate", part 3]

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Jan Beulich <JBeulich@novell.com>
Reviewed-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Rik Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
[v10: Fixed  fs: move code out of buffer.c conflict change]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-01-23 16:06:24 -05:00